Designing an Adequate Control Group



Science is all about observation with the goal of inferring relationships between variables, usually of the cause and effect variety. But the problem with observation is that it can be biased, especially when it comes to inferences of causality or even simple association. A good grant proposal must demonstrate how causal inferences will be made and, in so doing, how bias in interpretation will be reduced. Causal connections can never be determined with absolute certitude. What scientists try to do is to increase the plausibility of the explanation that variation in one variable is caused by variation is the other variable, that changes in one variable cause changes in another variable. Control groups are important in increasing confidence in causal inferences by reducing the plausibility of alternative explanations. A control group is essential to inform us if change in our dependent variable can be attributed to change in an independent variable. This chapter provides guidance on designing a control group that will meet the needs of your research design.


Social Capital Sexually Transmit Infection Causal Inference Teen Pregnancy Regression Discontinuity 
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© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.UCLA Program in global Health, David geffen School of MedicineUniversity of CaliforniaLos AngelesUSA

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